The present invention relates to a rotor device with a laminated core arrangement, which has a plurality of axial bores for the conduction of a coolant, and with two rotor pressure rings, between which the laminated core arrangement is fixed axially. The present invention relates, furthermore, to an electric machine having a rotor device of this type and to a corresponding method for cooling a rotor device.
Where electric machines of higher power are concerned, rotor cooling is often necessary. A corresponding electric machine is known, for example, from the document U.S. Pat. No. 2,610,992. The stator and rotor laminated cores described there have air cooling ducts running axially.
In order to execute ventilation more uniformly in the axial direction, ventilation of the rotor on both sides may be provided. The German laid-open publication DE 44 13 389 describes, for example, such an electric machine. It possesses two rotor laminated cores arranged at an axial distance from one another on a common shaft, two stator laminated cores arranged at a corresponding distance from one another and a cooling device which has an air conveyance device and cooling ducts running in the axial direction. The latter, as a result of the axial distance between the laminated cores, are subdivided in each case in two portions and are connected to the air conveyance device in such a way that the flow passes through the two portions of each cooling duct in opposite directions. In the annular space between the laminated cores, the cooling air is deflected from an axial direction into a radial direction, or vice versa. The axial distance between the laminated cores is in this case selected such that the flow cross section available in the annular space between the laminated cores for the cooling air is approximately equal to the sum of the flow cross sections of all the cooling ducts issuing directly into this annular space. However, this type of contradirectional cooling is highly complicated.